无缝伸缩缝沥青胶结料高温性能指标区分评价

为优选无缝伸缩缝沥青胶结料类型,提高无缝伸缩缝弹塑体高温稳定性,对选用的3种无缝伸缩缝沥青胶结料分别开展沥青基本性能试验、动态剪切温度扫描试验和多应力蠕变恢复试验,采用软化点、车辙因子与相位角,以及蠕变恢复率和不可恢复蠕变柔度等指标来评价3种无缝伸缩缝沥青胶结料的高温性能,并进行一致性和区分度分析,最后结合沥青混合料车辙试验进行验证.试验结果表明:受弹塑体中沥青胶结料聚合物掺量高及其高延迟弹性恢复能力的影响,国内外现行关于无缝伸缩缝沥青胶结料规范采用的软化点、车辙因子等指标对无缝伸缩缝沥青胶结料高温性能评价的一致性存在偏差,而基于多应力蠕变恢复试验的黏弹特性指标具有较好的一致性,且区分度明显.因此推荐采用区分度和一致性更可靠的多应力蠕变恢复试验作为评价无缝伸缩缝沥青胶结料高温性能的关键控制指标.     

沥青胶结料老化后的性能研究

研究老化对沥青胶结料性能的影响,选用三种具有代表性的改性沥青进行加速老化试验,通过对比沥青胶结料老化前后常规指标得出了沥青胶结料抗老化的能力,为高海拔地区沥青混合料的配合比设计提供参考。     

Sasobit温拌剂对橡胶沥青流变性能的影响

通过试验,从高温流变性能、低温流变性能、抗老化性能三方面,分析了Sasobit温拌剂对橡胶沥青胶结料的影响,结果表明:Sasobit温拌剂的加入对橡胶沥青的高温性能有一定的改善作用,但是会对其低温性能和抗老化性能造成不利的影响,综合考虑各项性能指标,其最优剂量选择在2.5%~3%之间。     

彩色非固化橡胶防水涂料主要原材料对产品性能的影响研究

以环烷油、芳烃油和石油树脂为原料,加入抗老化剂、除味剂等高效助剂及颜填料后,制得了安全环保并能够改善施工环境、延长建筑物防水寿命的彩色非固化橡胶防水涂料;探索了软化油添加量、石油树脂添加量、改性剂添加量等因素对彩色非固化橡胶防水涂料性能的影响;各原材料影响产品的不同性能指标,需综合考虑、优化配方,才能得到性能优良的产品...     

不同试验方法的老化沥青疲劳性能研究

通过旋转薄膜烘箱试验(RTFOT)和压力老化试验(PAV),对70~#基质沥青、苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性沥青、高黏沥青(HV)和基于化学改性原理的SBS/橡胶复合改性沥青(SRC)进行短期老化和长期老化,采用温度扫描试验、时间扫描试验、多重应力蠕变恢复(MSCR)试验和线性振幅扫描(LAS)试验对4种沥青的疲劳性能进行了研究.结果表明:SRC沥青的疲劳性能和抗老化能力最佳;温度扫描试验不能很好地区分不同沥青的疲劳性能差异;时间扫描试验可有效表征4种沥青的疲劳性能,但其耗时较长;MSCR试验中出现了平均弹性恢复率(R_(0.1)和R_(3.2))在长期老化之后大于短期老化之后的情况,其指标规律性和适用的沥青范围尚不明确;LAS试验可以表征沥青在重复荷载作用下的累积损伤发展过程,得到的损伤特征曲线和疲劳方程可有效评价各种沥青的疲劳性能.     

彩色弹性透水路面胶结料及其混合料的路用性能研究

针对现阶段透水路面的强度与耐久性较差问题,结合城市道路路面降噪的需求,提出了基于聚氨酯的复合树脂作为胶结料,用工业固废橡胶颗粒替代混合料中部分集料,研究彩色弹性透水路面胶结料及其混合料的路用性能特征。基于胶结材料的拉伸试验测得拉伸强度及断裂伸长率、混合料劈裂试验的湿干比确定复合树脂中聚氨酯与改性剂环氧树脂的组成;通过对开级配彩色弹性树脂混合料进行车辙试验、小梁弯曲试验、冻融劈裂试验和浸水肯塔堡飞散试验,研究混合料的路用性能及其受复合树脂胶结料用量影响的规律。结果表明:复合树脂中环氧树脂占聚氨酯的最佳掺量宜为10%;彩色弹性开级配混合料具有优良的路用性能,动稳定度和低温弯曲应变为10000次/mm和16000με以上,冻融劈裂比大于85%;综合胶结料对混合料的最宜用量为12%,能完全适用于重交通道路。     

橡胶沥青混合料高温性能评价指标的试验研究

以国内道路工程中常用的基质沥青与橡胶粉拌制橡胶沥青混合料,然后通过大量室内车辙试验对橡胶沥青混合料动稳定度与橡胶沥青胶结料177℃旋转黏度、软化点、针入度之间的相关性进行研究.结果表明:橡胶沥青混合料动稳定度与胶结料177℃旋转黏度及软化点之间相关性良好,胶结料177℃旋转黏度及软化点可以作为橡胶沥青混合料高温性能的评价指标.美国评价标准(ASTM D 6144—97)中177℃旋转黏度与软化点值偏低,如按该标准进行胶结料的质量控制,沥青混合料动稳定度可能难以满足国内关于聚合物改性沥青规范(JTJ F40—2004)的要求,故在室内试验的基础上,结合国内实际工程的经验,提出了橡胶沥青混合料高温性能评价指标值.橡胶沥青混合料高温性能受到不同性质橡胶粉的影响很大.     

彩色沥青胶结料的研究与应用

论述了彩色胶结料研制的历史过程、合成机理及方法;无色胶结料及其混合料的试验方法及性能分析;彩色混合料的应用效果。     

彩色沥青的研制与生产

为了适应人居环境的需要，我们进行了多次筛选，若干组配，试验及其性能分析，研制一系列相关指标满足不同路用性能要求的透明胶结料。将胶结料，颜料及具有一定级配的彩色石料抖制成彩色沥青混合料，再经摊铺，碾压形成彩色路面。实现彩色沥青国产化与系列化。     

彩色路面用胶结料的研究

介绍一种用于彩色路面的浅色胶结料的研制机理,并分析了影响该胶结料性能的主要因素。所研制出的胶结料与国外同类产品性能相当,兼具道路沥青的粘结性、柔韧性、抗水性以及与集料的粘附性等工程性质性能,在弹性、韧性方面略胜一筹。     

仓储式橡胶沥青零剪切粘度的确定

首先,运用低频率震荡测试法对基质沥青、仓储式橡胶沥青及其RTFOT短期老化产物进行了测试;其次,运用图形外延法、Cross模型拟合法及Carreau模型拟合法对各材料的零剪切粘度进行了测定;最后,对基质沥青进行了蠕变恢复试验,通过蠕变阶段和恢复阶段沥青的应变响应的计算,得出了静态施载作用下基质沥青的零剪切粘度。研究表明：基质沥青在低频震荡测试中,随着频率的降低会进入粘度稳定阶段,可以用图形外延法得到零剪切粘度;然而对于RTFOT老化后的橡胶沥青,在测试条件下未进入粘度稳定阶段,无法通过图形外延法测算零剪切粘度;由Cross模型拟合的结果都大于同样材料Carreau模型拟合结果。     

C30水泥基彩色地坪混凝土的制备与工程应用

通过调整胶凝材料组成与用量、选用优质粉煤灰、掺入高性能聚羧酸减水剂、优选性能稳定的无机颜料,研制出工作性能与力学性能良好、颜色均匀一致的C30水泥基彩色地坪混凝土,并通过采取一系列质量控制措施,将该混凝土成功应用于成都东区音乐公园工程中,取得了良好的实施效果。     

Aging analysis of rubberized asphalt binders and mixes using gel permeation chromatography

This study was initiated to investigate the aging characteristics of binders due to the reaction with the crumb rubber. For this laboratory study, the crumb rubber modified (CRM) and control binders were aged using an oven aging method. Also, asphalt mixtures with CRM or control binders were made and subjected to short-term and long-term aging treatments. The properties of these aged binders were evaluated using gel permeation chromatography (GPC) test procedures. The results from this study showed that: (1) the higher CRM percentage resulted in the higher large molecular size (LMS) value of asphalt binder under the binder aging conditions, and the rate of increase in the LMS value was found to have a relation to the CRM percentage. The asphalt binders with higher CRM percentages (15% and 20%) had a trend the LMS values decrease after a certain level. This finding is thought to be related to the required time for the rubber to be fully digested; (2) after subjecting to the long-term oven aging, the asphalt mixtures with the control and CRM modified binders were found to have statistically insignificant differences in aging level, measured using the LMS values. The very thin film thickness of binder in asphalt mixture and the aging temperature of 100 °C insufficient to enable a reaction were considered to be the main reasons that no differences were observed from the standpoint of the aging effect.     

隧道石粉取代胶凝材料对机制砂混凝土性能的影响

以石粉部分取代混凝土中的胶凝材料,研究石粉取代量为0, 10%, 15%, 20%, 25%, 30%时的机制砂混凝土性能,测试混凝土抗压强度、抗硫酸盐侵蚀、碳化深度、抗氯离子扩散系数等性能指标。结果显示,当水胶比、石粉细度固定时,混凝土性能随石粉取代量增加而降低;当石粉取代胶材量为15%、石粉细度为30%、水胶比为0.5时,28d抗压强度大于34.5MPa。     

高性能纤维增强水泥基复合材料(HPFRCC)的制备及其力学性能研究

采用常规的材料及通用的工艺力法,通过加入不同纤维、降低水胶比、去除粗骨料等方法配制抗压强度接近100 MPa的高性能纤维增强水泥基复合材料,并进行抗压强度、抗折强度、抗拉强度、静力弹性模量等力学性能试验,结果表明:高性能纤维增强水泥基复合材料不但具有较高抗压强度,其韧性及变形能力良好,适应现代工程结构的发展需要。     

Plasticity role in strength behavior of cement-phosphogypsum stabilized soils

Dredged soil and phosphogypsum are frequently regarded as wasted materials, which require further treatment to control their environmental impact. Hence, phosphogypsum is proposed as a binder to stabilize dredged soil, aiming at efficiently reducing and reusing these waste materials. In this study, the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unconfined compression tests, and the effects of plasticity index of original soils on the strength improvement were identified. Then, the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength improvement. The results revealed that the unconfined compressive strength significantly decreased with the increase in plasticity index at the same binder content. The essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH), and ettringite (Aft). The normalized integrated intensity of cementitious materials (CSH + CAH + Aft) by pore volume decreased with the increase in plasticity index. Consequently, the density of cementitious materials filling the soil pores controlled the effectiveness of strength improvement. More cementitious materials per pore volume were observed for the original soils with lower values of plasticity index. That is, the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious components. It can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.     

The effect of crumb rubber modifier (CRM) on the performance properties of rubberized binders in HMA pavements

The application of crumb rubber modifier (CRM) in asphalt mixtures is intended to improve the properties of binder by reducing the binder’s inherent temperature susceptibility. During the interaction with asphalt binder, the CRM particles absorb a portion of the oils in asphalt binder and the particles swell; therefore increasing the viscosity and stiffness of the CRM binder. Still, the performance properties of CRM binders in hot mix asphalt (HMA) pavement are considered to be unclear due to the various interaction effects of CRM with asphalt binders, depending on the CRM percentage, source and size. In this study, a laboratory investigation was conducted on the properties of CRM binders as a function of CRM processing method and percentages. A total of twenty-four CRM binders (3 binder sources * 2 CRM processing methods * 4 CRM percentages) were produced and artificially aged through an accelerated aging process. Evaluation of the CRM binders included the following testing procedures: Viscosity at high temperature, performance properties at high and intermediate temperatures, and cracking properties at low temperature. The results from this study indicated that the higher CRM percentages for CRM binders seemed to lead to a higher viscosity, a better rutting resistance and a less chance for low temperature cracking. In general, the ambient CRM was found to be more effective on producing the CRM binders that are more viscous and less susceptible to rutting and cracking.     

沥青瓦用彩砂及其性能要求

从沥青瓦用彩砂标准的角度,介绍了适用于沥青瓦的彩砂的原料要求及制备工艺,并对标准中彩砂主要性能指标的确定作了说明。